Foundation.



No. 825,903. PATENTED JULY 17, 1906. L. G. HALLBERG.

FOUNDATION.

APPLIUATION FILED A1124. 190s.

W/ TNESSES:

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UNITED STATES PATENT oEEroE.

FOUNDATION.

Specification of Letters Patent.

Patented July 17, 1906.

Application filed April 24, 1903. Serial No. 154.080.

T0 @ZZ whom t may concern:

Be it known that I, LAWRENCE GUs'rAv HALLBERG, a citizen of the UnitedStates, residing at Chicago, in the county of Oook and State ofIllinois, have invented certain new and useful Improvements inFoundations, of which the following is a specification.

My invention relates to foundation structures, and has forits object toprovide a novel and efficient foundation to serve as footings or basesadapted to support columns and walls of buildings.

In constructing foundations for use on compressible soil it is necessaryto spread the load of the walls and columns over a more or less extendedarea or surface, and for this purpose foundations are employed whichusually consist of layers of metal rails or beams embedded in masses ofconcrete and which are generally termed floating foundations by reasonof the fact that they are placed or extended over more or lesscompressible soil. This construction has proved to be very expensive,for the reason that the rails or beams merely provide a resistance totransverse strains, and therefore a large amount of metal is required.Moreover, the amount of metal employed correspondingly diminishes anddivides the mass of concrete and diminishes its resistance; Also infloating founda tions the line or point of weight or load is within thearea of the foundation, so that the upward pressure of the earth has atendency to break or shear the foundation approximately at about theline of connection of the load and foundation. There is a constantleverage upon the foundation at or near the line ofload, which tends tobreak or fracture it.

According to my present invention the rails and beams above describedare replaced by a system of anchor-rods which extend outward from orbeyond the point or line of load and are firmly anchored in the concreteof the foundation. By this construction Iutilize the tensile strength ofthe rods as a substitute for the resistance to transverse strain of therails and beams previously employed, the tension in the rods beingopposed to the compression in the concrete. By this means an increasedload-carrying capacity may be obtained by employing a greatly reducedamount of metal.

My invention consists in the organizations and arrangements of partshereinafter described, and pointed out in the claims.

In the accompanying drawings, which form a part of this specificationand illustrate the application of my invention to the support of wallsand columns, Figure l is a side View of part of a foundation structureconstructed in accordance with my invention and representing a sectionof a footing for awall. i Fig. 2 is a transverse sectional view throughthe structure of Fig. l. Fig. 3 is a top plan view of the structureshown in Fig. 1 when the rods are set and before they are covered withconcrete. Fig. 4 is a side elevation of a pier adapted to support acolumn and constructed in accordance with the present invention. Fig. 5is a bottom plan view of the construction of Fig. 4. Fig. 6 is a sideview of a part of a foundation structure for two columns or walls. Fig.7 is a top plan view of the foot ing shown in Fig. 6, showing thearrangement of anchor-rods in dotted lines and Fig. 8 is a sectionalview on the line 8 8 of Fig.- 6.

In the accompanying drawings the reference-letter A denotes as a whole afoundation structure suitable for use as a floating footing or base andcomposed of a mass of concrete in which anchor-rods a are embedded. Therods are securely anchored in the concrete by providing them with anysuitable means to prevent them from slipping in the concrete or toprevent any relative movement between the rods and the concrete. Forthis purpose I prefer to provide them with heads a. The foundation thusconstructed is adapted for use in sustaining walls or piers or other loads, and in the drawings I have shown the application thereof as a baseor footing for various purposes.

Referring more particularly to the form shown in Figs. l, 2, and 3, theweight, such as the wall of a suitable building, is indicated by thereference-letter a2 and rests upon or is supported by the base orfooting A, provided with anchor-rods a. The pressure of the wall isexerted in its line within the area of 1the footing or base A, and theearth upon which the base rests exerts an upward res'- sure on all partsof the under face of the ase, so that there is a tendency to break thebase by this leverage, which tendency generally shows itself at aboutthe line 0f connection of the wall and base or footing. The base orfooting is therefore provided with a series of anchor-rods a, arrangedin a row or layer extending longitudinally of the footing' and with theindividual rods transverse or at right angles to the line of the wall.It is obvious that any tendency of the foundation to shear IOO IIO

or crack by the compression of the load or weight will eXert a strain inthe direction of the length of the rods to stretch the latter. By thismeans the tensile strength of the rods is employed against thecompression in the concrete caused by the load. As the rods are firmlyanchored in the concrete they are secured against lengthwisedisplacement, and no change can take place in the base or footingbeyond. the wall or load unless the rods vstretcher the concrete abovethem is crushed. The tensile strength of the metal of therods is therebysubstituted. for the resistance to transverse strain or bending momentumof the beams and rails previously employed, and the tendency of the baseor footing to break or shear by reason of the leverage between the earthand load is obviated. The same system is employed in pier constructions,as shown more particularly in Figs. 4 and 5,where the footing or base isin the form ofa pier provided with the rods similarly anchored in theconcrete and running in two or more directions. In these gures thesupport for the column is indicated by the reference-letter a3, whichrests in the line of the center ofthe pier or base and practically abovethe crossingpointsV of the several layers of rods a. In thisconstruction I prefer to employ two main series or layers of rods, onesuperposed upon the other, with more or less intermediate cement, andextending at substantially right angles to each other, with two otherlayers or series of similar rods arranged to substantially bisect theangles between thefirst two or main layers to take care of the trianglesof concrete between the main layers, as clearly shown in Fig. 5. All ofthe rods of the different layers are provided with suitable heads a",whereby they are securely anchored within the concrete. This arrangementof rods prevents the fracture of the base or pier and holds it securelytogether, the effects being produced in substantially the same manner asin the construction described in connection with Figs. l to 3.

In some cases it is desired to support separated loads, as two walls,upon the outer lines or ends of the same footing or base7 as shown at a4at in Fig. 6. Under ordinary conditions these end loads would fracturethe concrete and the ends would settle down and cause the intermediatematerial to bulge or buckle up. By employing my invention I am able `andperform the same functions.

to obviate all such ,defects in this type offoundation, as will beapparent from the organi- Zation shown in Figs. 6, 7, and 8. In thisform the cross-rods a are similar in construction and arrangement tothose illustrated in the other figures and act in the same manner Inthis construction the base or footing is provided with auxiliarylongitudinal rods c5, which eX- tend along the length of the base orfooting and are provided with suitable heads a6 to securely and firmlyanchor them in the concrete thereof, so they will act as cantalivers.Some of the longitudinal rods a5 are bent, preferably in invertedcatenary curves, as shown in Fig. 6. This arrangement of devicesprevents the concrete from buckling up in the middle and from crackingunder the strain of the weights or loads at the ends, as indicated at(L4, because if any buckling occurs it mustA be by stretching the rods,and as the rods are firmly anchored in the footing or base and cannotstretch it follows that they prevent this tendency to buckle and crack.The cantaliver construction is employed when it is required to carry theload at the outer line of one or both ends of the footing or base, in'which case the end loads would tend to fracture the concrete and by thesettling of the under portions would cause the center or intermediateportions of the footing or base to bulge upwardly. By embeddinganchorrods in inverted catenary curves the loads at the ends cannotchange the footing or base unless the rods are stretched or the mass ofconcrete below them is crushed. The cate- Inary curves of the barsprevent the shearing of the concrete both transversely and longi-`tudinally.

Having described my invention, I claim- A foundation comprising a baseof cementitious material, headed anchor-rods embedded therein anddisposed substantially transversely to the longitudinal line thereof,and a series of longitudinal headed anchorrods embedded in the saidmaterial and form- IOO

